Operation of catalytic converters



May 4, 1937. E. J. HOUDRY ET AL l v2,078,950

` I OPERATION 0F CATALYTIC CONVER'EHS Filed June 4, 1935 2 sheets-'sheet1 FUE L May 4 1937 E.'J. HouDRY ET AL 2,078,950

OPERATION 0F CATALYTIC CONVERTERS Y Filed June 4. 1935 2 Sheets-Sheet 2HEATER ffrfaf/vfx Patented May 4, 1937 OPRATION F CATALYTIC CONVERTERSEugene J. Houdry, Philadelphia, Pa., and Thomas B. Prickett, Woodbury,N. J., assignors to Houdry Process Corporation, Dover, Del., acorporation of Delaware Application June 4, 1935, Serial No. 24,844

7 Claims.

This invention relates to temperature control of reaction vessels. It ismore particularly concerned with controlling the temperature of portionsof a reaction chamber or zone containing a contact mass which maypromote, enter into, or in any way assist chemical transformations.'I'he invention is especially directed toward converters havingoperative cycles comprising alternate periods of exothermic andendothermic re- 10 actions.

One object of the invention is to hold a wall of the reaction chamber atsubstantially constant temperature during both periods of the operativecycle. Another object is to prevent large internal stresses in the Walland other portions of the converter and .warpage `or deformation causedby such stresses. Still another object is to main- 'tain those portionsof the contact mass adjacent the chamber wall at reaction temperatureduring the exothermic phase of the operative cycle. Still furtherobjects will be apparent from the detailed discussion which follows.

In one form of converter to which the invention is directed the fluidreactants for each period of 25 the operation cycle are admitted to amanifolding chamber vor zone in contiguity with the reaction chamber orzone and separated from the latter by a perforated partition extendingacross the converter. The reactants then pass through 30 the partitionand into the mass. If desired, they may be distributed throughout thedepth and cross section of the mass by any suitable means, includingperforated conduits such as those disclosed and claimed in the U. S.Patent No. 1,987,904 issued January 15, 1935 to Eugene ,l. Houdry.

'I'he temperatures of those portions of the converter shell bounding theImanifolding chamber and of the face of the perforated partition to- 40Ward that chamber closely follow the temperatures f lluids contactingthem. The temperature of the contact mass is controlled to some extentby the temperature of entering reactants, but tends to go up or downwith exothermic or uid in. heat exchange relation with the mass as tindicated for example in thecopending application of vEugene J. Houdryand -Raymond C.

60 Lassiat. serial Number 728,544,111ed June 1, 1934.

V endothermic reactions, the amount of tempera-v manifolding chamber thewall temperatures of A the latter drop sharply toward the temperature ofthese uids while the temperature of the mass adjacent the manioldingchamber drops slowly or even rises. Thus, portions of the convertercommon to the manifolding and reaction chambers, as for example, theperforated partition and the converter walls, are subjected to internalstresses, caused by unequal rates of contraction within themselves oreven opposed contraction and expansion. In some instances, thesestresses become high enough to cause deformation or warpage of theseportions of the converter. It is evident that when the transition isfrom exothermic to endothermic reactions unequal and non-compensatingrates of expansion and contraction also tend to produce warpage of the'converter structure. Stiffening or supporting members are sometimesprovided for the perforated partition, particularly when the lattersupports the weight of the contact mass and/or a series of fluiddistributing members. In such instances, the tendencies of the partitionto deform with changes in temperature of fluids entering the converterare intensied. The supporting members themselves are subject todeformation and/or pulling loose from their supporting fastenings withthese temperature changes. One method of obviating the above dilcultiesis by directly heating certain portions of the converter, as forexample, after the manner disclosed in the copending application ofThomas B. Prickett, led February 10, 1934 and bearing Serial No.710,612.

The present invention contemplates f correcting the undesirabletemperature conditions by control of the temperature of the reactantsand involves feeding uid reactants for each period of the operationcycle to the converter at or near the same temperature. The reactantsfor the endothermic reaction are heated to reaction temperature orslightly above and admitted to the manlfolding chamber and thence to thecontact mass and for the subsequent exothermic reaction the reactantsareheated to the extent necessary to maintain the walls of the manifoldingchamber at a substantially constant temperature, thus avoiding rapidAand extensive changes `in temperature of these portions of theconverter structo the above function, the heated reactants for theexothermic reaction period maintain the mass adjacent the perforatedpartition at a temture with respect to the remainder. In additionperature level more nearly coincident with that of the main body of themass.

One application of the invention is in the utilization of a contact massalternately in transformation or treatment of hydrocarbons at onetemperature level, say '150 to 900 F. and in regeneration at a highertemperature, as at 900 to 1100 F. The hydrocarbons are usually heated toslightly above reaction temperature, as to '170 to 925 F., and fed tothe converter during a transformation period. In the subsequentregeneration, the regenerating medium, as for example, a stream ofoxygen bearing uid, such as air or a mixture of air and inert gaseousdiluents, is heated in any desirable manner to bring it within or nearthe temperature of the stream of hydrocarbons, as to '750 to 850 lF. Theinlet temperature of the regenerating medium is determined by thedesired temperature for the walls of the manifolding chamber, especiallythe perforated partition. Following a hydrocarbon transformationeffected at substantially 825 F. and during a re' generation at about1050 F., an inlet temperature of the regenerating medium ofapproximately 800 F. holds the partition at substantially 825 F. Anylowering of the temperature of the partition tends to check or retardthe rate of regenera tion of the mass which is adjacent the partition.

Concrete embodiments of the invention are disclosed in the accompanyingdrawings, in which:

Fig. 1 is an illustration of one form of the invention showing apreferred form of the converter in section;

Fig. 2 is a diagrammatic representation,of a modified form of theinvention; and

Fig. 3 is a diagram representing a still different modification.

In Fig. 1 converter X preferably covered with suitable heat insulatingmaterial such as lagging 4 is divided into end manifolding chambers Aand B and centrally located reaction chamber C by perforated partitionsor iiue sheets 5 and 6. Fluid reactants for either exothermic orendothermic reactions supplied selectively by valved lines Il or 22 passthrough T I8 to enter manifolding chamber A and are distributeduniformly throughout the depth and cross section of contact mass Mdisposed in reaction chamber C by a series of nested distributingmembers or perforated conduits 1 while fluid reaction products aresimultaneously vented from a plurality of points in mass M into a seriesof perforated outlet conduits l, substantially as described in thecopending U. S. application of Eugene J. Hendry, Serial No. 611,362, ledMay 14, 1932 which issued on June 2, 1936 as Patent No. 2,042,468. MassM may be of any known or desired type capable of effecting the desiredtransformation or treatment of the starting material but is preferablyin the form of bits', fragments, or molded pieces for regeneration inplace and when utilized in the transformation of hydrocarbons mayconform to those disclosed in the copending applications of Eugene J.Houdry, Serial No. 600,581 led March 23,- 1932 and Serial No. 35,101,filed August "l, 1935. The fluid reaction products are discharged intomanifolding chamber B and thence into T II to ent'er valved line I2 orvalved line I3. Nested conduits l and 9a embedded in mass M serve toconduct a plurality of streams of cooling or heating fluids byreversed.flow in heat exchange relation with mass M to remove heat fromthe latterf dining the exothermic reaction period and/or to supply heatto mass M 'during the endothermic reaction period. Manifolds I0 and I0ain nested relation supply the heat exchange fluid to and remove thisfluid from conduits 9 and 8a. A continually fresh supply of heating orcooling fluid may be used, or the fluid may be recirculated throughconduits 9 andv 9a anda suitable cooling system, as for example, thecircuits described in the aforesaid copending U. S. application ofEugene J. Houdry and Raymond C. Lassiat.

Partition 5 is provided with ribs or stiffening members I4 to assist itin supporting the weight of contact mass M and conduits 1. Members Ilmay be an integral part of partition 5, substan tially as shown or theymay be individual members attached, if desired, to partition 5 in anysuitable manner and supported from the latter or the wallsof converterl'or both. Whether attached to partition 5 or not or supported from thelatter and/or the walls of manifolding chamber A it is important thatmembers I4 be maintained at substantially the temperature of partition 5to prevent deformation of these members and/or loosening of theirsupporting fastenings.

Reactants for the endothermic transformation are conducted by line I5from a suitable source of supply to heater I6. of any suitable type,wherein they are heated tothe desired reaction temperature or slightlyabove, as to 750 to 925 F., in instances where the charge comprisescertain types of hydrocarbon materials, as for example, light and heavyoils or vapors. The heated reactants are then conducted through valvedline I1 and inlet T I8 into manifolding chamber A, whence they areadmitted to reaction chamber C, as described above. The reactionproducts are vented from the converter through outlet T II and intovalved line I2 leading to equipment for recirculation, storage, heating,cooling, fractionaiton, or any other desired treatment.

Reactants for the exothermic reaction are fed into a heater 2l by lineI9 where they are heated to substantially the temperature of theendothermic reactants by direct or indirect heat exchange withcombustion products from a suitable fuel conducted to heater 2| by line20. The exothermic reaction products are vented from the converterthrough outlet T II and line I3. Regenerating medium, such as air, isefficiently and economically raised to the desired temperature, to 800F., for example, in direct heat exchange with combustion products from afuel, as by commingilng with and supporting combustin of a controlledamount of the latter. The direct heat exchange heater avoids thedifficulties and expense of the' erection, operation and maintenance ofcertain indirect heat exchange furnaces, such as pipe stills or thelike, which often must be constructed of expensive alloysteelsparticularly when they are intended to handle air and corrosivefluids at high temperatures.

Whereas, in the embodiment disclosed in Fig. l, the exothermic reactantsare heated to the desired temperature in a single stage, Fig. 2illustrates two stage heating of these reactants. Exothermic reactionproducts leaving converter Xa by valved line I3a enter heat exchanger23a wherein they impart heat to the exothermic reactants being suppliedby line Ila. The heated reactants are further heated to thepredetermined temperature level in heater 2Ia of any desirable type andare conducted thence into converter Xa by'valved line 22a. Thetemperature of the regenerating fluid may be raised to the range of 300to 600 F. in exchanger 23a and to 4 heater 2 la.

or-,converters Xa and Xb may constitute 'some' not limited in itsessence to the specific formsw l tively, may be like the range of 750 to850 F. in the second stage In Fig. 3, the exothermic reactant fluids,such as'air or the like are supplied by line I 9b. 'I'he iluid is splitinto two streams which iiow through valved conduits lsb' and |9b2,respectively, the proportionate amounts of these two streams beingcontrolled by the valves in conduits |9b' and |9b2. One stream isconducted into combustion chamber 2lb' of heater 2lb where it commingleswith fuel supplied byline 20h and is heated to` variation ormodification of the converter structure shown in Fig. 1 or they may beof any diierc ent construction which is adapted for use in carrying outthe process described herein.

With control of the proportionate amounts yof regenerating medium..heated by indirect heat exchange alone and by both direct and indirectheat exchange, this iluid can be simultaneously heated to the desiredtemperature, such as 750 to 850 F. and vcommingled with a predeterminedand controlled amount of` diluting combustion fumes.

` It isapparent from the above that the invention presents improvementsin the operation of converters whichsimplify problems met in the designand use of the same. 'I'he invention is and examples disclosed hereinfor the purpose of illustration and explanation. The converter may be ofany type adapted for processing uids lwhich enter alternately intoendothermic and y exothermic chemical reactions. The invention Iisapplicable whether the converter is operated in horizontal, oblique,upright, or inverted` posil tion.

of operation as will to eliminate combustible We claim as our invention:V,

1. In the temperature control and operation of a converter fortransforming fluid reactants providing a reaction zone containing acatalytic mass and a iluid maniiolding zone Aadjacent thereto andseparated therefrom by a metal partition member but communicatingtherewith, said mass being adapted to be employed alternately 'on-streamto 4eflect the desired transformation of reactants and in regenerationin place -deposits or contaminants which accumulate thereon during theonstream or reaction period, the process steps which comprise during theori-stream and regeneration reaction periods of the the fluid reactantsinto and through said manifolding zone in contact with said partitionmember and then into said reaction zone,l the reactants being suppliedat such respective temperatures during each of the periods of the cyclemaintain said partitionat approximately constant temperature throughoutthe zwhole cycle of the reaction zone cycle of operation passingoperation, and maintaining at the temperatures desired y thereinprimarily by removing or adding heat with an independent heat exchangemedium circulated within said reaction zone but out of contact with themass containedtherein.

2. In the temperature control and operation of a converter providing areaction zone and manifolding zoneadjacent to and separated from saidreaction zone but communicating therewith,

said reaction zone containing a catalytic mass adapted for use inalternate endothermic and exothermic, periods of reaction fortransforming hydrocarbons and regenerating said mass in place v toeliminate therefrom combustible deposits or contaminants whichaccumulate thereon during the transforming reaction period, the processsteps which comprise,

during the endothermicy ing the said endothermic period, into andthrough l `3. In the temperature control and operation of a converterproviding a reaction zone and an inlet manifolding zone adjacent to andseparated from said reaction zone but communicating therewith, saidreaction zone containing a catalytic mass adapted for use in alternateendothermic and exothermic periods of reaction for transforminghydrocarbons and regenerating said mass in placcato eliminate therefromcombustible deposits or contaminants which accumulate thereon during thetransforming reaction period, the process steps which comprise duringthe endothcrmic and exothermic'reactions heating the reactants toapproximately the respective temperatures desired within said reactionzone, passing said` heated reactants into and through said manifoldingzone and into said reaction' zone, and maintaining the reaction zone atthe desired temperatures during each of said reaction periods byremovingor adding heat byfan independent heat exchange medium circulated` withinsaid reaction zone but out of contact with the mass containedl therein,so that during each t I period of; the cycle zone is' 'maintainedmatingl lthat of the said reactionzone "andthe portionsjoi the converterseparating said maniof operation the manifolding t0 -avoid deleteriousto temperature changes.

at a temperature approxi-j, 'i 702` foldinggzon'e from said reactionzone'are at all times y'during -the cycle of operation maintained' jwith'inafv suiliciently restricted temperature range y stresses ordistortions dl.1e"7"s"..f`

' within said reaction zone 4. In the temperature control and operationof a converter providing a reaction zone and an inlet manifolding zoneadjacent to said reaction zone and separated therefrom by a partitionmember but communicating with said reaction zone, said reaction zonecontaining a catalytic mass adapted for use in a cycle of operationinvolving alternate periods on-stream to effect the desiredtransformation of hydrocarbons and in regeneration in place to removecombustible deposits or contaminants therefrom,. said regenerationhaving a strong exothermic heat of reaction and said on-streamtransformation having only arelatively small heat of reaction,

the process of treating, while maintaining said partition member withina sufficiently narrow temrperature range so as to avoid distortionthereof due to temperature changes, which comprises heating hydrocarbonreactants to such a temperature, approximating that desired within saidreaction zone during the on-stream period, as will hold said partitionmember h at approximately the means of the temperatures desired withinsaid reaction zone during the Whole cycle of operation, feeding saidreactants through said manifolding zone in contact with .said partitionmember and into said reaction zone for a period of transformation,during which combustible deposits or contaminants accumulate on the masscontained in said reaction zone, then in a subsequent regenerationperiod passing a regenerating medium through said manifolding zone incontact with said partition member and into said reaction zone at suchdifferent temperature as will also hold said partition member atapproximately the said mean of the temperatures desired during the wholecycle of operation, and maintaining said reaction zone at desiredtemperature during the regeneration period by removing heat -With anindependent heat exchange medium. circulated Within said reaction zonebut out of contact with the mass contained therein. I

5. In the operation of a converter providing a reaction zone'and a fluidmanifolding zone adjacent thereto and separated therefrom by a metalpartition member but communicating therewith, said reaction zonecontaining a catalytic mass adapted in alternate periods of the cycle ofoperation to effect transformation of hydrocarbons and to be regeneratedin place by an oxygen-containing fluid to remove combustible deposits orcontaminants which become deposited thereon during the on-streamorreaction period, the process steps which vcomprise heating hydrocarbonreactants to a temperature substantially within the range of 750 to 925F., feeding the heated hydrocarbons through said manifolding zone indirect contact with said partition member and then through the latterinto said mass .during the on-stream or transformation period,- in thesubsequent regenerating period feeding an oxygen-containing regeneratingmedium through saidmanifolding zone into said mass, at such atemperature within-the aforesaid temperature lrange as to minimize oravoid stresses in said partition member, and circulating a heat exchangefluid in heat exchange relation with the mass but out of contact withthe latter during the cycle of operation, at such temperatures as tomaintain move deposits Vfrom said mass at the desired operatingtemperatures.

6. In the temperature control and operation of a converter providing areaction zone and an inlet manifolding zone adjacent to and separatedfrom said reaction zone, but communicating therewith,y said reactionzone containing a catalytic mass adapted for use in alternate periodshaving different heats of reaction for transforming hydrocarbons andregenerating said mass in place to eliminate therefrom combustibledeposits or contaminants which accumulate thereon during the on-streamor reaction period, the process of maintaining the portions of saidconverter common to both said reaction zone and said manifolding zone atsubstantially constant temperature during both periods of the cycle ofoperation of the converter comprising the steps of heating thehydrocarbon reactants to a temperature Within the range of 770 to 925F., feeding the heated reactants through said manifolding zone and intosaid reaction zone containing said catalytic mass for a period oftransform.h ation of said reactants, in the subsequent regenerationperiod heating a fluid regenerating ymedium to a temperature Within therange of 750 to 850 F. and feeding the latter through said manifoldingzone and into said reaction zone to remove deposits from the ysaid masscontained therein, and during the cycle of operation maintaining thecatalytic mass at the temperatures desired therein by removing or addingheat with an independent heat exchange medium circulated within saidreaction zone but out of contact with the mass contained therein.

7. In the temperature control and operation of a converter providing areaction zone and an inlet manifolding zone adjacent to and separatedfrom said reaction zone, but communicating therewith, said reaction zonecontaining a catalytic mass adapted for use in alternate periods havingdifferent heats of reaction for transforming hydrocarbons andregenerating said mass in place to eliminate therefrom combustibledeposits or contaminants which accumulate thereon during the on-strearnor reaction period, the process of maintaining the portions of saidconverter common to both said reaction zone and said manifolding zone atsubstantially constant temperature during both periods of the cycle ofoperation ofthe converter comprising the steps of heating thehydrocarbon reactants to a temperature within the range of '770 to 925F., feeding the heated reactants through' said manifolding zone and intosaid reaction zone containing said catalytic mass for a period oftransformation of said reactants, in the subsequent regeneration periodheating an oxygen-containing regenerating medium to a temperature ofapproximately 800 F. and feeding the latter through said manifoldingzone and into said reaction zone to rethe said mass contained therein,'and during the cycle of operation maintaining the catalytic mass at thetemperatures desired therein vby removingv or adding heat with anindependent heat exchange medium circulated within said reaction zonebut out of contact' with tl .e mass contained therein.

EUGENE J. HOUDRY. THOMAS B. PRICKETT.

cER'rIFIcA'rEoL` CORRECTION.

Potent No, 2,078,950. Mayf4, 1937.

EUGENE J. HOUDRY, ET AL.

is lhereby certified that 'error appearsv in the printed specificationof the above numbered patent requiring correction as follows: Page 4.,lfirst co1umn, line 25,- claim' 4, for "means" read mean;v and that thesaid Letters Patent should be read with this correction therein that thesame may conform -tc the record of the case in the Patent Office.

Signed-and sealed this- 29th dey of June', A. D. 1937.

Henry Van Arsdal'e ActingV Commissioner of Patents.

(Seal)

